Air compressor



April 13 1926. 1,580,435

F. D. HOLDSWORTH AIR COMPRESSOR Orzal Filed April 22, 1918 6 Sheets-Sheet l 7S 1 74 /27 o 46 06 'ff 58 M7 y] 306 a 4 11 J- 7 g/ y '31: o f o d30am ft' l.. i 70" o j /7 d?? my a 37 Q d l l I 89 /y 'o 1 fm l 205 4@ 84 207 ff 127 4, a5 8f 88 w f 4a J9 gz li l o2 Mmm l 6.3 m I 37 51 /44 J2 I g i w i /4 1i j w J9 y0 215 i f A mi .F o f 4 :5 0 z a d 207 ff l 1 1 Il d 60 April 13 1926.

ur a@ 1,580,435 F. D. HoLDswoRTH AIR COMPRESSOR Original Fi'led April 22, 1918 6 SheetsLSheet 2 #59 l fr f7 F1a nl a 46 A g l f J7 n F a M 44, 74

April 13 1926. 14.580.435

F. D. HoLDswoRTH AIR COMPRESSOR Original Filed April 22, 1918 6 Sheets-Sheet 5 Aprl`13 ,41926.

F. Dv HOLDSWORTH AIR COMPRESSOR Original Filed April 22,

6 Sheets-Sheet i April 13, 192e. 1,580,435

F. D. HOLDSWORTH .un coMPREssoR Original Filed April 22, 1918 6 Sh`eets-Sht 5 April y13 1926. 1,580,435

F. D. HoLDswom-H AIR COMPRESSOR Original Filed April 22, 1918 6 Sheets-Sheet 6 Patented Apr. 13, 1926.

UNITED STATES PATENT. OFFICE.

FRED D. HOLDBWOBTH, 0l' WHO, NEW HAMPSHIRE, ABSIGNOB T6 SULLIVAN ILGHINEBY COMPANY, A CORPORATION 0F MASSACHUSETTS.

un. conrnnssoa Application iled April 22, 19.18, Serialk No. 229,989. Renewed Kay 27, 1924. 4

To all whom it may concern.'

Be it known that I, FRED-D. HoLoswon'rH, a citizen of the United States, residing at Claremont, in the county of Sullivan and State of New Ham shire, have invented certain new and use l Improvements in Air Compressors, of which the following is a full, clear, and exact specification.

This invention relates to compound or multiple stage air or gas compressors, and

more particularly to compressors of the marine type, and has for its general obJect the rovision of a highly e cient but exceedingly light and compact machine of this character. In this connection, it will be understood that, for use upon shipboard, and es ecially upon war vessels, machines ca; piible of rapidly delivering compressed air or` gas in relatively large quantities and under a very high degree of compression are required, but that the weight permissible in such machines, and the space available for their accommodation, are extremel limited,

my invention having among its o jects the" revision of a machine satisfactorily meetin these conditions.

ore particular objects of the invention, together with means whereby the same may be carried into eiect, will best be understood from the following descri tion of one form or embodiment thereof i ustrated in the accom anying drawings. It will be understood, liowever, that the particular construction and arrangement described and shown has been chosen for illustrative purposes merely, and that the invention, as defined by the claims hereunto appended, may be otherwise embodied without departing from the s irit and scope thereof.

In said rawings,-

Fig. 1 is a plan view, and Figs. 2 and 3 elevations from opposite sides respectively, of the complete machine.

Fig. 4 is a vertical section of the cooling tanks taken substantially on the line 4 4,

Fig. I3.

ig. 5 is an enlar d longitudinal vertical section of the com ete machine, taken substantially on line E-IL Fig. 1, certain pipe connections being omitted for purposes of clearness.

Fig. 6 is an end elevation of the complete machine as viewed from the left in Fig. 2 or from the right in Fig. 3.

Fig. 7 is an enlarged vertical sectional view of the valve devicesvfor the high pressure cylinder, the plane of this section being substantially the same as that of Fig. 5.

Fig. 8 is a similar view of the valves for the second intermediate c linder.

Fig. 9 is a detail vertical sectional view of the inlet and discharge valves for the first intermediate c linder, taken substantially on the line 9-9, igs. 6 and 17.

Fig. 10 is a detail vertical sectional view of one of the relief valves for the cooling tanks, the same being taken substantially on the line 10-10, Fig. 6.

Fig. 11 is a 4detail horizontal sectional view of one of the discharge valves for the low pressure cylinder, the 4same being taken substantially on the line 11-11, Fig. 2.

Fig. 12 is a similar view of one of the inlet valves for the low pressure cylinder, taken substantially on the line 12-12, Fi 3.

Fig. 13 is an elevation, partly bro en away, of the flywheel.

Fig. 14 is a. detail vertical section of the water inlet for one of the cooling tanks, the

.same being taken substantially on the line 14-14, Fig. 15.

Fi 15v is a detail horizontal section on the line 15-15, Figs. 4 and 14. Fig. 16 is a detail vertical section, substantially on the line 16-16, Fig. 3, of the inlet air chamber for the low pressure cylinder, the inlet valve being omitted. i

F ig. 17 is a detail horizontal section, taken substantially on the line 17-17, Figs. 6 9 and 18, of the air inlet chamber for theiirst intermediate cylinder.

Fig. 18 is a detail vertical section on the line 18-18, Figs. 1 and 17.

In order that the invention may best be understood, the neral construction and arrangement of t e several essential parts of the mechanism will first be outlined, and their coo eration explained, after which the preferre construction of these and other puits will be described more in detail.

Referrin particularly to Figs. 1, 2, 3, 5, and 6, 25 enotes, as a whole, the machine frame, which provides the necessary supports, bearings, and guides for tlie various parts of the mechanism, except as hereinafter pointed out. Said frame comprises two upright portions 26 in which is journaled a crank shaft 27 carr ing between said u right rtions a fiywhee 28. At its ends e cran shaft 27 is connected by pitmen 29 with yokes 30 extending about the crank shaft and to the upper ends of .which are rigidly secured the compressor piston rods 31, and to the lower ends of which are rigidly secured the steam piston rods 32, each of said piston rods 31 being substantially in alignment with a corresponding steam piston rod 32. Secured to the piston rods 32 are steam pistons 33 working in steam cylinders 34 secured to the bottom of the frame 25 and constituting bases therefor, the admission of steam to said cylinders being controlled by slide valves 35 of any well known type o eratively connected, by means hereinafter escribed, with the crank shaft 27.

The invention is herein shown as embodied in a four-stage compressor comprising a low pressure cylinder 36 having a low pressure iston 40, a first intermediate cylinder 3 having a piston 41, a second intermediate cylinder 38 having a piston 42, and a high pressure cylinder 39 having a high pressure piston 43. Said cylinders are arranged in pairs at opposite ends of the machine and are supported at the top of the machine frame 25 directly above the upright portions 26. The cylinders ofeach pair are disposed in tandem relationship, so as to form, in effect, a single compound cylinder having two piston portions or c ambers, and the pistons for each compound cylinder or pair of cylinder portions are secured to one of the piston rods 31. Located between the compressor cylinders, and supported by a suitable platform 44 at the top of the fiiame, is a pair of cooling tanks 45 and 46 through which the air passes after its compression in each cylinder and before reaching the next successive cylinder for further compression. This disposition of the cooling tanks between the compressor cylinders provides an exceedingly compact construction, as well as a very convenient one, inasmuch as the air can be conveniently passed through said tanks in its passage from one cylinder to the next succeeding without materially changing its normal path or course.

As herein shown, the low pressure cylinder 36 is combined in one pair with the second intermediate cylinder 38, while the first intermediate cylinder 37 is combined with the high pressure cylinder 39, the pistons 40 and 42 being mounted upon one of the iston rods 31 and the pistons 41 and 43 eing mounted upon the other of said piston rods. In each pair, the smaller cylinder, representing a relatively higher stage of compression, is superimposed upon the larger cylinder, representing a relatively lower stage of compression, thereby provi ing a very com act, symmetrical, and stable arrangement. e compression takes place at the under sides of the pistons 40 and 41 and at the upper sides of the pistons 42 and 43, so that it will be seen that in the construction shown the cylinder heads throu which the piston rods 31 pass are those suijected to relatively low pressures in the several stages of the operation, thereby reducing the difficulties ot' packing the piston rods to a minimum.

It will, of course, be understood that all of the compressor cylinders are provided with suitable inlet and exhaust valves (whose construction will he hereinafter more fully described), whereby air may be drawn into said cylinders and discharged therefrom after compression therein. Atmospheric air enters the low pressure cylinder 36 through an air inlet 47 (see Figs. 1 and 3) and after compression therein passes, by a pipe 48 (see Figs. 1 and 2), to a coil 49 (see Fig. 4) in the cooling tank 45, downwardly through said coil, and thence through a chamber 50 (Figs. 2 and 6) and pipe 51 to the first intermediate cylinder 37. After further compression in t e cylinder 37 the air is conveyed through a pipe 52 (Fig. 2) passing through the bottom of the cooling tank 45 to the top thereof, and thence downwardly through a eoolin coil 53 from which said air is conveyed through piping 54 (Figs. 1, 2, and 3) to the second intermediate cylinder 38. After still further compression in the cylinder 38, the air passes by a pipe 55 (Figs. 1 and 3) to the top of the cooling tank 46 and thence downwardly through a coil 56 (Fig. 4) in said tank to a pipe 57 (Figs. 3 and 6) leading to the high pressure cylinder 39. After final compression in the cylinder 39, the air passes by a pipe 58 (Figs. 1 and 6) extending through the bottom of the cooling tank 46 to the top thereof and thence downwardly through a coil 59 (Fig. 4) in said tank to a receiver 60 having an outlet 61 (Fig. 3) whence said air may be conducted, by suitable means, to its point of utilization or to a suitable storage receptacle.

The air system above described may, if desired, be provided with suitable relief or safety valves, such valves being shown, for example, at 62, 63, and 64 (Figs. 2 and 6) in the connections between the several cylindels. The receivers 50 and 60 are preferably provided with suitable drainage cocks 65 and 66, respectively, (Figs. 2 and 3) for the withdrawal of any water ofcondensation which may accumulate therein; and similar drain cocks may, if desired, be provided at other points in the air system, as shown, for example, at 67 and 69 in Figs. 2 and 6.

The general organization, arrangement, and o eration of the complete apparatus having t us been outlined, the referred `construction of the parts referre to, as also of certain auxiliary devices, will now be described.

Steam is supplied to the valve chests 7 O of v ing to any suita the steam cylinders 34. from any suitable source through pipes 71 (Fig. 3) communieatin with a supply ipe 72 having a suitable inlet valve 73, tie admission of said steam being controlled by a governor 74 of any suitable type actuated through beveled gearing 75 and chain and sprocket gearing 76 from the crank shaft 27. The exhaust ports of the valve chests are connected with an exhaust pipe 7 7 (Figs. 2 and 3) leadle point. she steam cyl1nders 34 and valve chests 70 are preferably provided with drainage valves 78 and 79, respectively, as shown in Fig. 3.

The steam valves 35 are operated by rods 94 passing through stutlin boxes 95 and connecked to slides 96 mounte carried by the machine fra-me. The slides 96 are connected by rods 97 to pms 98 projecting from disks 99 secured by bolts 106 and pins 107 in eccentric relation to the crank pins 100 to which are connected the pitinen 29. The eccentrically mounted disks 99 are formed with internal annular grooves 101 communicating with passages 102 in the crank pins 100 and leading to the periphery of the latter. The eccentric pins 98 are provided with axial passa es 103 which extend from the inner faces o the eccentrics 101 to oil cups 104 at the outer en ds of said pins, said passages 103 communicating through radial passages 105 with the peripheres ofl said eccentric pins. Lubricant supplied to thc oil cups 104 enters the passages 103, a portion of said lubricant passing through the passages 105 to the periphery of the eccentric pins 98 for lubricating the latter, and the remainder of said lubricant reaching the inner faces of 'the eccenti'ically disposed disks 99 and,rbeing thrown by centrifugal force into the grooves 101, finds its way through the grooves 102 to the perrplierics of the crank pins 100 for lubricating the latter. The portions of the grooves 101 which communicate with the assages 102 are. slightly more remote from t ie centers of rotation of the eccentrically disposed disks 99 than the other portions of said grooves, whereby the lubricant is caused to accumulate at the outer ends of said passages 102 for ready entry thereinto.

Referring to Figs. 5 and 13, lthe flywheel 28 is mounted on the shaft 27 between the uprights 26, and between the substantially rigidly connected motor and compressor units or couples, and in order to facilitate the assembly of the parts, which might otherwise be ditlicult on account of such position of the flywheel, said tiywheel is preferably composed of four semi-circular parts 108, 109, 110, and 111, constituting two sets. The parts 108 and 109, which constitute one set, collectively form a complete annulus or split wheel comprising spokes 112 and rim 113, said rim being formed at one edge in suitable guides with a flange 114 which is engaged by a flange or annular rib 115 on the members 110 and 111, which constitute the other set and also collectively form a complete annulus or auxiliary rim rtion. The members 108 and 109 may readily assembled about the shaft 27, and after such assembly the members 110 and 111 are placed in position thereon in staggered relation thereto, and are secured to said members 108 and 109 by means of bolts 116.

Referring to Fig. 2, water for the cooling stem may either be supplied under a suita le head through a pipe 80, controlled by a cut-olf valve 81, or may be drawn from a lower source through a i 82, controlled by aout-off valve 83. llli pipes 80 and 82 unite in an inlet pipe 84 for a centrifugal circulating pump 85 supported by a suitable bracket 86 on the machine frame, the shaft 87 of said pump being operated by chain and sprocket gearing 88 from the crank shaft 27. A discharge pipe for the pump 85 is formed with two branches 89 and 90 leading, respectively, to the water jackets of the cylinders 36 and 37, which' jackets, as hereinafter more fully described, communicate with' the jackets of the cylinders 38 and 39, respectively, From the upper part of the jacket of the cylinder 38 a water pipe 91 (Fig. 3) communicates with the bottom of the cooling tank 46, while a similar water pipe 92 (Fig. 2) leads from the upper art of the jacket of the cylinder 39 to the ottom of the cooling tank 45. A water outletpipe 93 (Fi 1) communicates with the to s of both coo ing'tanks 45 and 46, whence t e overflow from said tanks may be conducted to any suitable point. From the foregoing it will be seen that the water from the pump 85 passes through the piipes 89 and 90, thence upwardly through the water jackets of ythe compressor cylinders, thence upwardlfy through the coolingl tanks 45 and 40. rom which it is disc arged through the pi e,9

he cooling tanks 45 and 46 comprise (see Fig. e41) sheet metal cylinders 120 having Hang. upper and lower edges secured, respectivel to the platform 44 (which con- \stitutcs a common bottom for both of said tanks), and to cover members by means of rings 122 and 123 engaging the flanges at the ends of said cylinders and' bolted or otherwise secured to the platform 44 and covers 121, respectively. The coils 49 and 53 are coaxially arranged, the latter within the former, in the tank 45. and thc coils 56 and 59 similarly arr within thc. tank 46, the several coils being suitably supported and spaced by uprights 124 to which said coils are secured, the lower ends of said uprights being bolted to the platform 44. Each of the water pipes 91 and 92 communicates with its respective or tops 121,`

cooling tank 46 or 45 through a, fitting 125 (see Figs. 14 and 15) bolted or otherwise secured in an opening in the platform 44, said tting having, within the tank, a hood 126 arran d to direct the incoming water substantia ly tangentially ot the tank, whereby said water is caused to flow through the tank in an approximately Spiral path from the bottom of said tank to the pipe 93 at the top thereof.

The sheet metal cylinders 120 above referred to provide a tank construction which is extremely light in weight but sullicientlyr strong to perform the function for which the tanks 45 and 46 are intended, it being seen that, in the normal operation of the machine, said tanks are not subjected to any considerable pressure or other strain. ln order to guard against the accidental development of internal pressure within said tanks, as by accumulation of air therein due to leakage into either tank from the air coils, said tanks are provided with relief valves, designated as a whole by the numeral 127 in Figs. 1, 4, and 5 (but omitted, to avoid confusion, from Figs. 2 and 3), the construction of one of these valves being illustrated in detail in Fig. 10. As shown in the latter figure, the top 121 of each cooling tank is provided with an opening 128 which is closed by a valve 129 provided with packing 130 secured thereto by a washer 131 and nut 132 on a threaded stem 133 projecting trom the lower or inner face of Said valve. The valve 129 is provided with an enlarged hollow stem 134 guided for vertical movement in a suitable opening in a yoke 135 secured to the tank top 121 by bolts 136 in threaded engagement with said top 121 and provided with nuts 137 bearing on said yoke 135. The Valve 129 is pressed to its matby a spring 138 within the hollow stem 134 and yengaging at its outer end a follower 139 which bears against a crosshead 140 having adjacent its ends openings to receive the bolts 136, said crosshead being engaged by nuts 141 on the threaded ends of said bolts. By adjusting the nuts 141 the tension of the spring 138 may be varied to cause the valve 129 to remain seated against any desired predetermined pressure in the tanks. In order to prevent injury to the spring 138 by moisture accumulating in the hollow interior of the valve stem 134, the latter is provided with a drainage port 210 communicating with said hollow interior.

Referring to Fig. 5, the lower head of the low pressure cylinder 36 is of hollow construction to provide a water chamber 142 with which the water pipe 89 communicates, said water chamber having passages 143 communicating with a water jacket or casing 144 surroundingr the c llnder proper. The jacket or casing 144 is flbrmed with air inlet and outlet chambers 145 and 146, respectively, (see also Figs. 2, 3, and 16) with the former of which the air inlet 47 communicates and from the latter of which the air pipe 48 leads. Communication between the chambers 145 and 146 with the interior of the lower end of the cylinder 36 is controlled by a pair each of inlet and discharge valves designated as a whole in Figs. 2 and 3 by the numerals 147 and 148, respectively.

The two inlet valves 14'( are exactly alike, and a description of one will suliice for both. Referring to Figs. 12 and 16, the wall of the cylinder 36 Vis provided adjacent its lower end with an opening 149 which registers with a similar opening 15() in the inner wall of the air chamber 145. Removably fitted tothe opening 150 is a valve seat 152 having air passages 153, said valve seat being held in place in said opening by means of a yoke 154 forced into engagement with said valve seat by an abutment screw 155 in threaded engagement with a cover 156 bolted or otherwise secured in place over an'opening 157' in the outer wall of the air inlet chamber 145. said opening 157 being in alignment with the openings 14S) and 150. By removing the cover 156 the valve seat 152 and parts carried thereby may be readily removed through the opening 157. Cooperating with the ports 153 in the valve seat 152, is an annular plate valve 158 normally held to its seat by an annular leaf spring 15S) interposed between said valve and a. flange 160 on a keeper or guide member 161 provided with air passages 162 and secured to the valve seat 152 by means of a screw or bolt 163. The walls of the air chamber 145 may, if de sired, be strengthened and supported by one or more spacing webs, one of which is indicated at 211 in Fig. 16.

The discharge valves 148, one of which is illustrated in detail in Fig. 11, are substantially identical with the inlet valves last de scribed except that. their position in the cylinder Wall is reversed, the inlet valves being of course arranged to permit inward flow only of the air, while the outlet valves are arranged to permit outward flow only thereof. The parts of the discharge valve shown in Fig. 11 are designated by the same numerals as the corresponding parts of the inlet valve shown in Fig. l2, with the exponent added, and will be fully understood without further explanation.

The second intermediate cylinder 3S. which is superimposed upon the low pres sure cylinder 36 and is arranged coaxxally therewith, is enclosed by a water jacket or casing 164 suitably bolted or otherwise secured to the jacket or casing 144 of the cylinder 36. the water chambers of said jackets communicating with one another through rts 165, and the water chamber of the )acket 164 communicating at its upper end with the water pipe 91 leading to the cooling tank 46. The jacket or casing 164 is formed with an air chamber 166 with which communicates the air pipe 54. The outer head 167 of the c lindei' 38 is secured to the jacket 164 by bo ts 168.

By reason of the difference in diameter of the cylinders 36 and 38, it will be seen that the volume of space enclosed between the pistons 40 and 42 will vary according to the position of said pistons, said space being less when said istons are at or near the limit of their u pward) stroke than when they are at or. near the limit of their downward stroke.

In order to avoid any loss of power due toV the useless compression of the air in the space between said pistons during their upward stroke, said space is preferably vented to the atmosphere by means of a passage 169 (see Fig. 16), formed in the bottom of the jacket 164, and communicating at one end with the top of the cylinder 36 and at the other with the 4air chamber 145 and thence with the atmosphere through the air inlet 47.

The inlet and discharge valve mechanism for the second intermediate cylinder 38 is shown in detail in Fig. 8. The upper wall of the jacket or casing 164 is provided with a tapered opening into which is litted a tapered bushing 170 having an axial port 171 communicatingr with the air chamber 166, a lateral port 172 communicating with a passage in the casing 164 leading to the upper end of the cylinder 38, and a second lateral port 173 communicating with a passage in the casin 164 with which the air pipe 55 is connecte The passage 172 communicates with the inlet passage 171 and discharge passage 173 through ports controlled, respectively, by an inlet valve 174 and a discharge valve 175, the former having a stem slidably mounted in the hollow stem of the latter, and the stem of the latter being slidably mounted in a sleeve 176 held in place by a crosshead 177 secured to the casing 16 by means of bolts 178 (see Fig. 1). The inlet valve 174 is normally held toits seat by a spring 179 interposed between the end of its stein and the end of the recess in the stem of the valve 175, while the latter valve is similarly held to its seat by a spring 180 interposed between the end of its stem and the bottom of the opening in the sleeve 176. Upon the down stroke of the piston 42 the valve 174 opens, permitting air to be drawn, through the ports or passages 171 and 172, into the cylinder, the valve 175 remaining seated: while on the up stroke of said piston thehvalve 174 is seated, and the compressed air forces open the valve 175 and passes through the ports or passages 172 and 173 to the pipe 55.

The construction of the first intermediate cylinder 37 (see Fig. 5) is similar to that of the low pressure cylinder 36, said cylinder 37 having a lower head 181 rovided with a water chamber with which t e water pipe 90 communicates, said water chamber communicating through ports or passages 182. with 'the water chamber of the jacket or casing 183, which in turn communicates through ports or passages 184 with the water )acket or casing 185 of the high pressure cylinder 39. Referring to Figs. 9, 17,- and 18, the cylinder head `or casin 181 is'provided with an air inlet 'champ r 186 with which the pipe 51 communicates, said chamber communicatin through an inlet valve, designated as a w ole by the numeral 187, with a passage 188 in the casing or jac et 183, sai passage communicating with t e lower end of the cylinder 37. Said passage 188 also communicates through a discharge valve, designated as a whole ly the numeral 189, with an air discharge chamber 190 in `the casing 183, said chamber 190 communieating with the air pipe 52. The inlet and discharge' valves 187 and 189 are substantially identical in construction with the inlet anddischarge valves 147 and 148 of the low pressure cylinder, and therefore require no description in detail. The valve 189 is secured in place by a yoke 191, similar to the yoke 154, said yoke being held in place by an abutment screw 192 carried b a cover 193 held in place by bolts 194 and c osing an opening 195 in the upper wall of the chainber 190. The valve 187 is held in place by a screw or bolt 196 passin through an opening in the lower wallo the chamber 186 and having a threaded end outside said chamber to receive a nut 197. The chambers 186 and 190 are formed in lateral extensions in the casings 181 and 183, respectively, and the opening 195 is in the upper face of said extension, the valves 187 and 189 being arranged in alignment with said opening, whereby both of said valves may be readily removed upon removal of the cover 193.

As in the case of the pistons 40 and 42 (Fig. b'), means are provided for preventing undue compression of air bewteen the pistons 41 and 43, said means comprising a vent for the upper end of the cylinder 37. As shown in Fig. 18, said vent comprises a passage 198 in the wall of the casing 183, said passage communicating at its upper end with the upper end of the cylinder 37 and at its lower end with an extension 212 (see also Figs. 9 and 17) of the air inlet chamber 186, the upper end of said cylinder 37 being thereby vented, not to the atmosphere, as in the case of the cylinder 36, but to the air inlet chamber 186.

The outer head 199 (Fig. 5) of the high pressure cylinder 39 is secured to the jacket or casing 185 of said cylinder by bolts 200 and is formed with a passage 201 (see also Fig. 7) leading from the upper end of said cylinder and communicating through inlet with a port or passage fact that the compression and discharge valves 202 and 203, respectivel with an air inlet chamber 204 with whic the air pipe 57 communicates, and 213 communicating with Ithe pipe 58. With the exception of a. difference in size,rcorresponding to tlie reduced volume of air, due to its compression, the construction of the valves 202 and 203 is substantiall identical with that of the valves 174 an 175 of the second intermediate cylinder, and require no further description in detail. 4

It will be observed that, by reason of the takes place at opposite ends, respectively, of the two cylinders of each pair, and consequently at opsite strokes of the corresponding steam piston 33, the work of said steam pistonis equalized. In order further to evenly distribute the work of the machine and the load upon the engines, the cranks on the shaft 27 are preferably arranged at approximately 90J from one another, so'that when the pistons in one pair of cylinders are atmidstroke the pistons of the other pair will be at the extremity of their stroke in one direction or the other and consequently substantially idle.

For draining the cooling system when the machine is not in use, suitable drainage valves may be employed at suitable points in the system, such valves being shown at 205 and 215 in Fig. 2, the valve 215 bein employed to empty the tanks 45 and 46 an the valve 205 to drain the water iping and cylinder jackets. Similarly, suita le unloading valves may be employed to relieve the air system of pressure after stopping the ap aratus, such a. valve being shown at 206 in ig. 3.

Suitable means are preferably employed for lubricatin the various moving parts of the machine, ut as the lubricating system (except as hereinbefore pointed out) forms no portion of the present invention, it is not shown nor described in detail herein. In the drawings, however, are indicated at 207 and 208 lubricating devices which may be of any usual or Well known type. While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in other forms without departin from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. A four stage compressor comprising, in combination, a high pressure cylinder, a first intermediate cylinder aligned therewith, pistons in said cylinders, a common piston rod for said pistons, a low pressure cylinder, a second intermediate cylinder aligned with said low pressure cylinder, pistons in said last named cylinders, a second piston rod to which said last named pistons are connected, and actuatn ativel connected with said piston rods.

2. f our stage compressor comprising, in combination, a high pressure cylinder, a first intermediate cylinder aligned therewith, pistons in said cylinders, a common piston rod for said pistons, a low pressure means opercylinder, a second intermediate cylinderaligned with said low pressure cylinder, pis- Ltons in said last named cylinders, a second piston rod to which said last named pistons are connected, a pair of motor cylinders, pistons in said motor cylinders, and means for rigidly connecting said motor pistons with saidvpiston rods, respectively.

3. A four stage compressor comprising,

in combination, a high pressure cylinder, a first intermediate cylinder aligned there;

with, pistons in said cylinders, a common piston rod for said pistons, said piston rod passing through the head of said intermediate cylinder, a low pressure cylinder, a second intermediate cylinder aligned with said low pressure cylinder, pistons in said last named cylinders, a second piston rod to which said last named pistons are connected,

said second piston rod passing through the head of said low pressure cylinder, and actuating means operatively connected with said piston rods.

4. In a multiple stage compressor, in combination, a compound cylinder comprising relatively high and low pressure cylinder portions of different diameters, an inlet chamber for said low pressure portion, inlet valves connecting said low pressure portion and said inlet chamber, and pistons in saidchambers respectively, said cylinder having a passage providing communication between the inlet and the space between the pistons.

5. In a multiple stage compressor, in coinbination, acompound cylinder comprising relatively high and low pressure cylinder portions of dilerent diameters, an inlet chamber for said low pressure portion, inlet valves for said low pressure portion, and a casing providing a cooling jacket for said cylinder and having a passage affording communication between said inlet and the space between said pistons.

6. In a multistage compressor, in combination, a compound cylinder comprising relatively high and low pressure cylinder portions of different diameters, inlet and discharge valves for each of said positions, pistons in said portions. and casings providing cooling jackets for said`cylinder portions respectively, the low pressure cylinder casing having an air chamber communicating with said low pressure portion and the high ressure cylinder casing having a passage a ording communication between said air chainber and the space between said pistons.

7. In a multiple stage compressor, in combination, a compound cylinder having an inletl and comprising relatively high and low ressure portions or chambers of difl'erent ameters, inlet and discharge valves for each of said chambers, pistons in said cham- Vbers of different diameters, pistons in said chambers, respectively, and a plurality of juxtaposed directly intercommunicatin casings Aproviding cooling jackets for sai cylinder portions, respectively, one of said casings having a passage affording communication between said inlet and the space between said pistons. Y

9. In a compound fluid compressor, the combination with a, cooler, of a high pressure cylinder located at one side of said cooler, an intermediate pressure cylinder alined with said high pressure cylinder, pistons in said cylinders, a common piston rod for said pistons, a low pressure cylinder located at the opposite side of said cooler, a second intermediate pressure cylinder alined with said low pressure cylinder, pistons in said last-nanied cylinders, a second piston rod to which said last-named pistons are connected, actuating means operatively con nected with said piston rods, and means for conveying the compressed Huid through said cooler after its compression in each of said cylinders.

10. In a compound fluid compressor, in combination, a frame, a cooling tank supported by said frame at the to thereof, compressor cylinders supported iy said frame at opposite sides of said tank, and means for conveying the compressed fluid through said tank 1n its passage from one of said cylinders to the other.

11. In a multiple stage fluid compressor, in combination, a cooler, a plurality of compressor cylinders corresponding to the several stages, each of said cylinders being located at the opposite side of said cooler from the cylinder or cylinders of the immediately preceding or succeeding stage or stages and means for conveying the compressed fluid through said cooler alternately in opposite directions in its passage from stage to stage.

12. In a multiple stage fluid compressor, in combination, a cooler, compound compressor c linders located respectively at opposite si es of said cooler and each comprising a plurality of cylinder ortions, pistons in each of said portions, and) means for conveying the compressed fluid through said cooler after its compression in each of said cylinder portions.

13. In a multiple stage fluid compressor, in combination, a cooler, compound compressor cylinders located respectively at opposite sides of said cooler and each comprising a plurality of cylinder portions, the several cylinder portions corresponding respectively to the several stages and each of said cylinder portions being located at the opposite side of said cooler from the cylinder portion or portions of the immediately precedin or succeeding stage or stages, pistons 1n each of said cylinder portions, and means for conveying the compressed fluid through said cooler alternately in opposite directions in its passage from stage to stage.

14. In a compound fluid compressor, in combination, a cooler comprising a plurality of cooling tanks, a plurality of compressor cylinders at cach side of said cooler, and means for conveying the `compressed fluid through said cooler after its compression in each of said cylinders.

15. In a multiple stage fluid compressor, in combination, a cooler comprising a plurality of cooling tanks, a plurality of compressor cylinders corresponding to the several stages, each of said cylinders being located at the opposite side of said cooler from the cylinder or cylinders ofthe irnmediately preceding or succeeding stage or stages, and means for conveying the compressed fluid through one or another of said tanks alternately in opposite directions in its passage from stage to stage.

16. In a multiple stage fluidcompressor, in combination, a cooler comprising a plurality of cooling tanks, compound compressor cylinders located respectively at opposite sides of said cooler and each comprising a plurality of cylinder portions, pistons in each of said portions, and means for conveying the compressed fluid through one or another of said tanks after its compression in each of said cylinder ortions.

17. In a multiple stage fluid compressor, in combination, a cooler comprising a pair of cooling tanks, compound compressor cylinders located respectively at opposite sides of said cooler and each obmprisiiiga plurality of alined cylinder portions, said cylinder portions corresponding respectively to the several stages and each of said cylinder portions being located at the opposite side of said cooler from the cylinder portion or portions of the immediately preceding or succeedin stage or stages, pistons in each of said cy inder portions, a common shaft to which all of said piston rods are connected, and means for conveying the coinpressed fluid through one or the other of 'nil said tanks alternately in opposite directions in its assage from stage to stage.

18. n a compound com ressor, in combination, a plurality of a igned/cylinders,

a plurality of directly intercommunicating cooling jackets for said cylinders, respectively, a cooler for the compressed fluid, means for supplying a coolin medium to one of said jackets, and means or conyeying said medium from another of said jackets to said cooler.

19. In a compound fluid com ressor, in combination, a cooling tank, jac eted compressor cylinders located at opposite sides of'said tank, means for conveying the coinpressedfluid through said tank 1n its assage from one of said cylinders to the ot er, means for su plying a cooling medium to the jacket of) one of said cylinders, and means for subsequently conveying said medium to said tank.

20. In a compound fluid compressor, in combination, a plurality of cylinders, a coolcr for the compressed fluid, and meansfor supplying a cooling medium to said cylinders successively and thence to said cooler.

2l. In a compound fluid compressor, in combination, a coolet` for the compressed fluid, a plurality ofacompressor cylinders at each side of said cooler, means for conveying compressed fluid throu h said cooler after its compression in eac of said cylinders, and means for supplying` a cooling medium to the cylinders at one side of said cooler, successive y, and thence to said cooler.

22. In a multiple stage fluid compressor, in combination,` a plurality of compound cylinders each having a plurality of cylinder portions, a plurality of coolingtanks, means for supplying a cooling fluid successively to theseveral portions of each of said cylinders, and means for conveying said fluid from each of said cylinders to one or the other of said tanks.

23. In a multiple stage fluid compressor, in combination, a plurality of compound cylinders each having a plurality of c inder portions, a cooler comprising a p urality of cooling tanks located between said cylinders, means for conveying the com` pressed fluid through said cooler after its compression in each of said cylinder portions. means for supplying a cooling fluid successively tp the several portions of each of said cylinders. and means for conveying said fluid from each of said cylinders to one or the other of said tanks.

f2-l. ln a compound [luid compressor, in combination. a plurality of cylinders, a plurality of cooling tanks, means for supplying a cooling fluid to cach of said cylinders, and means for separately conveying said fluid from each of said cylinders to one or another of said tanks.

In a fluid compressor, a cooler comprisin a base or platform and a plurality of u right sheet metal cylinders secured to Said Base and constituting a plurality of cooling tanks, said base forming a common bottom for all of said tanks arranged side by side thereon.

26. In a compound fluid compressor, in combination, a frame, a base or platform supported by said frame at the top thereof, a plurality of u right sheet metal cylinders secured to said ase and constituting aplurality of cooling tanks, said base forming a common bottom for all of said tanks, compreqr cylinders sup orted by said frame at opposite sides of said tanks, and means for conveyin the compressed fluid through one or the ot er of said tanks in its passage between said cylinders.

27. In a fluid compressor, in combination, a shaft having'a crank pin, a motor operatively connected with said crank pin, compressing means operatively connected with said crank pin, a disk eccentrically 'carried by said crank pin, a pin carried by said ecccntrically mounted disk, a valve for said motor, and a rod connected to said eccentric Vpin'for operating said valve, said eccentric pin having a lubricant passage, said eccentrically mounted disk having an internal annular groove adapted to receive lubricant from said passage, and said crank pin having a lubricant passage communicating with said groove. i

28. The combination with a crank pin and a pitman journaled thereon, of a disk eccentrically secured to said crank pin, a pin carried by said eccentrically mounted disk, and a rod journaled on said eccentric pin, said eccentric pin having a lubricant passage, said eccentrically mounted disk having an internal annular groove adapted to receive lubricant from said passage, and said crank pin having a lubricant passage communicating with said groove.

29. A multistage compressor comprising a plurality of motor cylinders, motor pistons therein, a plurality of compressor cylinders disposed in alinement with said moitor cylinders, a plurality of compressor pistons therein, a crank shaft between said motor and compressor cylinders, driving connections between said motor pistons and said crank shaft and compressor pistons, and a cooler disposed in the space between said compressor cylinders and wholly to one side of said crank shaft.

30. A multistage compressor comprising a plurality of motor cylinders whose axes lie in a plane making an angle with the horizonta motor pistons therein, a plurality of compressor cylinders disposed in alinement with said motor cylinders, a plurality of compressor pistons therein, a crank shaft whose axis lies in the same plane with the axes of said cylinders, but at right angles compressor cylinders and above said ily wheel.

31. A multistage compressor comprising a pair of motor cylinders whose axes lie in a plane making an angle with the horizontal, motor pistons in said ylinders, a pair of compressor cylinders isposed in alinement with said motor cylinders, compressor `pistons in said compressor cylinders, a crank shaft driven by said motor pistons, driving connections between said motor pistons and said compressor pistons, a ily wheel on said crank shaft between said driving connections, and a cooler disposed in the space between the outer ends of one of said pairs of cylinders and the periphery of said fly wheel and between the cylinders of said pair.

32. In a multi-stage fluid com ressor, in

combination, a. low pressure cylin er, a high pressure cylinder and two intermediate cylinders, a cooler com rising a plurality of cooling tanks locate adjacent said cylinders, means for conveying the compressed Huid from said low and first intermediate cylinders through one of said tanks and for conveying the compressed fluid from the second intermediate and high pressure cylinders through the other of said tanks.

33. In a multi-stage fluid com ressor, in

` combination, a low pressure cylin er, a high pressure cylinder, an intermediate cylinder arranged in alinement with said low pressure cylinder, another intermediate cylinder arranged in alinement with said high pressure cylinder, a cooler comprising a pluralit of cooling tanks arranged adjacent sai cylinders, and means for conveying the compressed lluid from said low pressure cylinder and one of said intermediate cyl inders through one of said tanks and for conveying the compressed fluid' from the other intermediate cylinder and the high pressure cylinder through the other of said tanks.

34. In a multi-stage fluid com iessor, in combination, a low pressure cylin er, a hi h pressure cylinder, an intermediate cylin er arranged in alinement with said low res'- sure cylinder, another intermediate c linder arranged in alinement with said hig preS- sure cylinder, a cooler comprising a plurality of cooling tanks arranged adacent said cylinders, one of said coolin tan being parallel to said cylinders an means for conveying the com ressed fluid from said low pressure cylin er and one of said intermediate cylinders through one of said tanks and for conducting the compressed duid from the second intermediate cylinder and the high pressure cylinder through the other of said tanks.

35. In a multi-stage fluid compressor, in

combination, a low pressure cylinder, a hi h pressure cylinder, an intermediate cylin er arranged 1n alinement with said low pressure cylinder, another intermediate c linder arranged in alinement with said high pressure cylinder, a cooler comprising a plurality of cooling tanks arranged adjacent said cylinders, both of said cooling tanks being parallel to said cylinders, and means for conveying the com ressed fluid from said low pressure cylin er and one of said intermediate cylinders throii h one of said tanks and for conducting t e compressed fluid from the second intermediate cylinder and the high pressure cylinder through the other of said tanks.

36. In a multi-stage Huid com ressor, in combination, a low pressure cylin er, a hi h pressure c linder, an intermediate cylin er arranged 1n alinement with said low pressure cylinder, another intermediate c linder arranged in alinement with said hig pres-v sure cylinder a cooler comprising a plurality of cooling tanks arranged adjacent said cylinders, one of said coolin tanks being parallel to said cylinders, an means for conveying the com ressed fluid from said low pressure cylin er and one of said tanks and for conducting the compressed Huid from the second intermediate cylinder and the high pressure cylinder Vthrough the other of said tanks, the fluid conducting means from said last mentioned cylinders comprising concentric coils in said tank arallel to said cylinders through both of w ich the compressed fluid flows downwardly.

37. A four-stage compressor comprising, in combination, a high pressure c linder, a low pressure cylinder, arrange parallel thereto, two intermediate cylinders, arranged one in alinement with each of said previously mentioned cylinders, pistons in all of said cylinders, connections between the pistons in alined cylinders` and driving means for said pistons including a steam cylinder and piston in alinement with one of said pairs of alined c linders and a crank shaft having an lary dis osed cranksA connected to sai pairs o compressor pistons.

38. A four-stage compressor comprising, in combination, a hi h pressure cylinder, a low preure cylin er arraiged parallel thereto, two intermediate cylin ers arranged one in alinement with each of said previously mentioned cylinders, pistons in all of said cylinders, connections between the stons in alined c linders, driving means or said pistons inc uding a steam cylinder and pieton in alinement with one of said pairs of @lined cylinders and a crank shaft having angularly disposed cranks connected to said pairs of compressor pistons, Aand cooling means for the tiuid compressed in said various cylinders including Ya pair of separate tanks each containin fluid conducting means frorn two of said cylinders.

39. In combination, in a compressor, a low pressure cylinder, a 'cylinder receiving compressed Huid from said low pressure cylinder and coo erating in tlre further compression thereofl? a crank shaft, an intercooler intermediate said cylinders, said cylinders and intercooler all lying to one side of a plane passing through said crank shaft means for supplying a cooling liquid to the bottom of said intercooler and discharging the saine at the top, and means for conducting the Huid from said first to said second cylinder causing the same to flow from the top to the bottom of said intercooler.

40. Th'e combination with a compressor, a low pressure cylinder, a cylinder receiving compressed Huid therefrom and cooperating in the further compression of said tiuid, an intercooler com rising a tank affording a cooling liquid c amber, means within said chamber constituting a conducting means for compressed Huid, means'for supplying a cooling liquid to the bottom of the chamber and discharging the same at the top, and means for conductinA the fluid from said rst mentioned cylinder to the top of said conductinfr means and leading it from the bottom ois the latter to said second mentioned cylinder.

41. In a multi-stage compressor, a. plurality of single acting cylinder and piston compressor couples and means for effecting coo eration of the cylinders and pistons of sai couples to effect multi-stage compression including iston rods connected to said pistons, a multi-crank shaft, means for effecting rotation thereof, operative connections between said piston rods and said shaft, said parts being arranged so that the piston rods of said low pressure piston and the First intermediate piston are under tension during the compression strokes of their respective pistons, and means for e'ecting reciprocation of said pistons including a fluid ressure actuated piston coaxial with said ow ressure piston and rigidlyl connected to tlie rod of the latter.

42. A. four-stage compressor comprising, in combination, a high pressure cylinder, a iirst intermediate cylinder alined therewith, pistons in said cylinders, operative connections between said pistons connecting them for simultaneous movements in like directions, a low pressure cylinder, a second intermediate cylinder alined with said low pressure cylinder, pistons in said last named cylinders, operative connections between said last named pistons connecting them for simultaneous movements in like directions, a crank shaft, and operative connections between said crank shaft and said pairs of pistons.

43. A multi-sta e compressor com rising, in combination, a ow pressure cylin er having a piston therein, an intermediate cylinder having a iston therein and adapted to receive the Hijiid compressed in said low pressure cylinder for the next stage of its compression, a hi li pressure cylinder having a piston therein and arranged in alincment with one of said first mentioned cylinders, said high pressure piston being connected to one of said first mentioned pistons for i'eciprocation therewith, and actuating means for said several pistons including separate actuating connections to said low pressure piston and said intermediate piston.

In testimony whereof I affix my signature.

FRED D. HOLDSWORTH.

having angularly disposed cranks connected to said pairs of compressor pistons, and cooling means for the fluid compressed in said various cylinders including a pair of separate tanks each containin fluid conducting means from two of said cylinders.

39. In combination, in a compressor, a low pressure cylinder, a cylinder receiving compressed fluid from said low pressure cylinder and cooperating in the further compression thereof, a crank shaft, an intercoolei` intermediate said cylinders, said cylinders and intercooler all lying to one side of a plane passing through said crank shaft, means for supplying a cooling liquid to the bottom of said inteicooler and discharging the saine at the top, and means for conducting the fluid from said first to said second cylinder causing the same to flow from the top to the bottom of said iritercooler.

40. The combination with a compressor, a low pressure cylinder, a cylinder receiving compressed fluid therefrom and cooperating in the further compression of said fluid, an intercoolcr com rising a tank affording a cooling liquid c amber, means within said chamber constituting a conducting means for compressed fluid, means for supplying a coolinrr liquid to the bottom of the chamber and discharging the same at the top, and means for conductini the fluid from said first mentioned cylinder to the top of said conductin means and leading it from the bottom o the latter to said second mentioned cylinder.

41. In a niulti-stagc compressor, a plu rality of single acting cylinder and piston compressor couples and means for effecting coo eration of the cylinders and pistons of sai couples to effect multi-stage compression including iston rods connected to said pistons, a multi-crank shaft, means for effecting rotation thereof, operative connections between said piston rods and said shaft, said parts being arranged so that the piston rods of said low pressure piston and the first intermediate piston are under tension during the compression strokes of their respective pistons, and means for effecting reciprocation of said pistons including a fluid ressure actuated piston coaxial with said ow ressure piston and rigidly connccted to the rod of the latter.

42. A four-stage compressor comprising, in combination, a hi h pressure cylinder, a first intermediate cylinder alined therewith, pistons in said cylinders, operative connections between said pistons connecting them for simultaneous movements in like directions, a low pressure cylinder, a second iiitei'mediate cylinder alined with said low pressure cylinder, pistons in said last named cylinders, operative connections between said last named pistons connecting them for simultaneous movements in like directions, a crank shaft, and operative connections between said crank sliaft and said pairs of pistons.

43. A multi-stage compressor com rising, in combination, a low pressure cylin er having a piston therein, an intermediate cylinder having a piston therein and adapted to receive the fluid compressed in said loiv pressure cylinder for the next stage of its compression, a high `pressure cylinder having a piston therein and arranged in alinenient with one of said first mentioned cylinders, said high pressure piston being connected to one of said first mentioned pistons for ieciprocation therewith, and actuating means for said several pistons including separate actuating connections to said low pressure piston and said intermediate piston.

In testimony whereof I afiix my signature.

F RED D. HOLDSWORTH.

Certificate of Correction..

It is hereby certified that in Letters Patent No. 1,580,435, granted April 1?, 1996, upon the application of Fred D. I'Ioldsworth, of C1aremont, New Hampshire, for

an improvement in Air Compressors, errors appear in the printed specification requiring correction as follows: Page 5. line i12, for the misspelled word bevvteeii read between; page 6, line 124, claim 6, for the word positions read portions: and

that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of J une, A. D. 1926.

M. J. MOORE, Acting Uommssoner of Patents.

Certificate of Correction.

It is hreby certified that in Lett/ers Patent No. 1,580,435, granted April 13, 1926, upon the appliation of Fred D. Holdsworth, of C1arem0nt, New Hampshire, for an improvement in Air Compressors,7 errors appear in the prin-ted specification requiring correction as follows: Page 5. line 112, *for the misspelled word bowee11- read b etween; page 6, line 124, Vclaim 6, for the word 1 positions read portions: nml that the said Letters Patent should be road with these corrections therein that the same may conform to the record of the caso in the Patent Office.

Signed and sealed this 15th day of J une, A. D. 1926.

M. J. MOORE,

[BML-l Actzng Commwswne'r of Patents. 

